Github's Custom Repo Image Card Support
With Github’s recent custom (per repository) Open Graph image support feature announcement, I wanted to test it out! Side note, this has been an open issue since March 2016.
Find it on any repo within the Settings Tab on Github.
Test Preview Image
Once you’ve uploaded a preview image, test it on Twitter: Link Validator or Facebook: Debug Sharing Link.
Post the thing
Then once all of that checks out, post it!